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will need to pass FDA muster, but at least for the 3 million cosmetic surgeries performed in the U.S. each year, it wouldn’t have to deal with insurance reimbursement hassles, because patients generally pay out of their pockets. If it were used for general surgery, it could tap a bigger market of possibly 20 million procedures a year or more, Dean says.
How is it supposed to work? The dose of the Excaliard drug is given after the wound is made, through an injection, not through a topical cream, Dean says. That makes it more useful for scars that cover small surface areas, like incisions. “This is not for burn victims,” Dean says.
Getting the dose, the delivery, and the sequence of operations right will be key to making this a success. Because when the body is wounded by an incision, a certain amount of immediate inflammation is natural and necessary to help the wound heal. Excaliard’s challenge is in determining when the inflammation has done its job, and when the remodeling of new scar tissue to seal the wound turns excessive.
Dean used an evolutionary example to make his point about how the body reacts to wounds and forms scars. If you were on the African savannah and got bitten by a lion, you’d want the wound to close up and heal as quickly as possible.
“Of course here in San Diego, people aren’t getting bitten by lions anymore,” Dean says. So that means the body is naturally inclined to overreact with not just inflammation, but growth factors to seal the wound over time, which would be good if it were the savannah, but not so much in a less dangerous environment. To be more specific, he said Excaliard is dampening this wound response by blocking a gene (which Dean isn’t disclosing yet) that triggers excess production of collagen and other fibrotic components that form bulky scars.
To build on this idea, Dean explained the wound healing process in three phases. First comes the inflammatory phase, in which white blood cells flock to the site of injury to ward off any foreign pathogens that might cause an infection once the skin is broken. That passes quickly, usually within a week, and is followed by more prolonged phases in which cells in the injured area proliferate and remodel connective tissue and growth factors to form a protective barrier around the wound.
“You want it to heal, but not scar,” Dean says.
The only competitor pursuing an idea like this is U.K.-based Renovo, which is further along with a pivotal clinical trial in Europe of a protein drug for scar reduction. Dean says his company’s drug is a specific small molecule (actually an oligonucleotide) that’s different from Renovo’s protein drug, and that the Excaliard treatment is designed to work through a different biological mechanism. But he didn’t say too much more about differentiating factors, or about the company’s clinical strategy.
He did, however, tell a fun little anecdote about the name. It is inspired by the legend of King Arthur, and the famous sword Excalibur, which was supposed to protect warriors from injury in battle. But Dean noted that it only worked in combination with the magical scabbard to protect it. Speaking metaphorically in this case, the drug is the sword, and the smooth, even scar is like the scabbard it needs to work in.